The objection to direct deposit is the access you grant a third party to your account. In the direct deposit agreement you sign with your employer there is a clause that allows them to withdraw any funds they may have overpaid or for other enumerated reasons.
So the problem that some see is if for whatever reason the third party withdraws in error from an account but the person spent the money already for honest reasons. The employee bounces his payments and it costs him penalties and fees. This is not including the possibility of fraud on either side.
My employer requires direct deposit. But I have had this service for two decades so I am not paranoid. I think I was the first at my banking institution to have direct deposit. However I do know that there can and in my case HAVE been snafus that cannot happen with paper checks. In one instance my employer double paid me then instead of withdrawing the overpayment withdrew the entire amount one day and the next reissued the correct amount. Had I not had the extra cash in my account to cover the day (end of the month Rent, and utilities) I would have bounced every bill I paid that month due to the access I granted my employer. The apologized up and down to me and the other 10 people in my department, but two of my coworkers were out close to $100 in bounced check fees and the embarassment that goes along with this kind of thing. In another instance a different employer neglected to deduct state taxes from my checks for a month. I didn't notice because it really wasn't all that much. But at the time I was living from paycheck to paycheck. When the employer found the error, without notifying me, they withrew the measly $30 they overpaid causing me to overdraw my account costimg me $39 in an overdraft fee. I received the notification of the correction by my employer the same day I found out I was overdrawn by $10!
Of course the answer is to make your direct deposit is, in general, safer and much more convenient than paper checks. But it isn't without its faults. My direct deposit account now holds only the previous check's ammount plus the minimum $500 to avoid fees and allow for the crappy interest the bank pay. Anything over that is immediately transfered to another account my employer cannot touch.
See ya
Tony